Refrigerator of the absorption type



July 3, 1928. v 1,675,474

- B. c. voN PLATEN ET AL REFRIGERATOR OF THhE ABSORPTION TYPE Filed om. e, 1925 7f3/fur A Tra/WYE y Patented July 3, 1928.

.UNITED STATES PATENT OFFICEA BALTZAR CARL VON PLATEN .AND CARL GEORG MUNTERS, OE STOCKHOLM, SWEDEN, ASSIGNORS, BY MESNE ASSIGNMENTS, T ELECTROLUX SERVEL CORPORATION, A.

CORPORATION OF DELAWARE. I

lREFmanaaronor THE ABsoar'rIoN TYPE.

Application led October 2, 192,5, SerialNo.. 60,088, and in Sweden September 15, 1925.

The present invention refers to refrigerators of the absorption type which are driven entirely by means of heat and in which the part or parts giving off heat are cooled by means of a cooling liquid, for instance water. The principal object of the invention is to provide safety means controlled by a factor influencing the normal operation l0 of the refrigerator, said means being adapted to control the heating means of .the

refrigerator on variations in said facton yThis control of the heating means is preferably such that the said safety vmeans brings I the heating means out of service, when said factorl attains a predetermined' value.

If said factor is the temperature within the refrigerator, for instance Within its condenser, said safety means may consist of a' B0 relay which is adjusted to a certain temperature so as to place said heating means out of service when said temperature has been attained, and to bring said heating means into service again, when the temperature decreases below the value, to which said relay is adjusted. In most cases said heating means consists .of an electric heatingl in no way limited to the embodiments illus--v trated.

In the drawingf-l l Fig. l is a diagrammatic section of a refrigerator of the absorption type having a relay adapted respectively to open and close the circuit ofthe electric heating means of the refrigerator according to the temperature within the condenser.

Fig. 2 is a sect-ion on the line II-II of Fig. 1.

Fig. 3 -is a view of the relay on an enlarged scale.

i 4 is a view'of another embodimentv of the safety means according to the invention.

First, a short description will'be given of the general construction and operation of the refrigerator shown in Fig. l.

1 designates a generator containing an absorption liquid in which a cooling agent is dissolved. In the followin description it may be assumed that the a sorption liquid is water, and the coolingvagent ammonia. Gaseous ammonia driven out in said generator 1 is conducted through the conduit 2 into a condenser 3 where the ammonia is caused to condense. The ammonia thus condensed flows through the conduit 4 into an evaporator 5, which is simultaneous] supplied with an inert as, for instance ydrogen, from the absor er 6, through the conduit7. In the evaporator 5, the ammonia evaporates, whereby heat is absorbed, said heat'being taken:l from the surroundings of. the evaporator 5. On account of the mixture of gaseous ammonia and hydrogen having a higher specific weight than the hydrogen, said mixture flows downwardly in the evaporator 5, and thenllows throu h the conduit 8 into the absorber 6, in which the gaseous mixture is brought into contact with weak ammonia solution coming from the generator 1 through the conduit 9 and a.

heat exchan er 10 inserted in said conduit 9. In the a sorber 6, said solution absorbs gaseous ammonia, and thel solution enriched 1n ammonia collects in the lower part of the absorber 6, from which it flows into the generator l through vthe conduit 11 and the heat exchanger 10. The conduit 11 is heated by means of an electric heating element 12, whereby the li uid in that'branch of the conduit 11 is riven upwards. When the gaseous ammonia is dissolved in the liquid inthe absorber 6, heat is generated, which heat must be led oil, and to this end the absorber 6 is provided with a cooling jacket 14 to which cooling liquid, for instance water,

is supplied through the conduit 15 and led away through the conduit 16 to the condenser 3, from which the cooling li uid is led awaythrough the conduit 17. T e hydrogen contained 'in the gaseous mixture ilowing from the eva orator 5 into the absorber 6 is not .absorbe by the absorption li uid but ascends the absorber on account o its' low specilic weight and is returned to the evaporator 5 through the conduit 7.

According to the invention a relay, designated in its entirety by 20, is suspended f at its lower end a circular opening, into which the relay 20 is inserted and mai`ntained by friction, and being otherwise U- shaped so that its resilient legs may be clam ed around the condenser (see especially ig, 2). The rela 20 comprises two contact pieces 22 an 23 (see especially Fig. 3), each secured to the free endsof two tongues 24 and 25 respectively, said tongues being secured in a foot 26 at the one end of a tube 27 consisting, for instance, of glass, which tube may be evacuated or filled with an inert gas. The one tongue 24 consists of two metal laminas of different coeiicients of expansion and soldered together so as to form a so called bimetallicor thermostat lamina, whereas the other tongue consists, for'instance, of steel. The tongue 24 is connected with one terminal of an electric battery 29 by means of a conducting wire 28, the other terminal of Said battery being connected to one terminal of the electric heating element'12, whereas the other tongue 25 is connected to the other terminal of said element 12 bymeans of a conducting wire 30.

The construction of the relay is previously' known, and in the present patent applica# tion no protection is claimed for such alrelay per se.

The operation is as follows:

If, for some reasonor other, the temperature in the condenser 3 and consequently also in the relay 2O rises and attains a predetermined value to which the relay is adjusted, the tongue 24 will be bent out from the tongue 25 on account of the different eXpanv limit to which restarting of the -re rigerator. stance, the rise of temperature resulted from an interruption in the supply of cooling liqsion of the two metal laminse of which said tongue 24 is composed, whereby the contact 22, 23 and, consequently, the circuit of the electric heating element 12 will be interrupted. By this means the refrigerator will be protected against any unpermitted rise of temperature which might otherwise cause bursting of the refrigerator or otherwisecausel injury thereto. When the refrigerator then cools, so that the temperature in the condenser 3 and, consequently, also in the relay 20 decreases below the temperature therelay 2() is adjusted, the contact 22, 23 will a am be closed, causing If, for in- A uid and said fault has been removed during the time in which the refrigerator has been out of service, the machine will resume its normal function, but if the fault is still at hand, the relay will again interrupt the cur-inventlon,

rent, as soon as the temperature in the condenser 3 attains the predetermined value.

Fig. 4 shows another embodiment of the relay which in this case has the form of an electric switch. Secured to the condenser 3. is a stirrup 31 in which a tube 32 is swingably mounted, said tube being made of electrically non-conducting material, for instance glass. Fused into the glass at each end of said tube 32 are two contacts 33, 34 and 35, 36 respectively, and in the tube there is a little body 37 of an electrically conducting material adapted to melt at the temperature at which the circuit is to be interrupted. Furthermore, there is secured on the condenser 3 a plate 38 of electrically insulating material, in which plate 38 two contacts 40, 41 are secured by means of screws 39 or the like, each of said contacts 40, 41v consisting of two resilient contact tongues, the outer ends of which are bent somewhat outwards so that the contacts on the tube 32 may easily engage between the respective tongues and make good electric contact therewith. The one pivot of the tube 32 is extended outwards, and securedl on said extension is a little band-wheel 42. Conducting wires 28 and 30 extend from the contacts 40, 41 f'to the battery 29 and the electric heating element 12. v

The operation is as follows:

When the temperature in the condenser 3 and consequently also inthe relay attains a certain value, the little metal body 37 melts and falls down onto the bottom of the tube 32, thus taking'up the position 371, whereby the circuit of the element 12 is interrupted. The tube 32 may then be swun half a revolution by means of the hand-whee 42, so that the contacts 35, 36, which in the ligure are shown at the lower end of the tube, are caused to en age the knife-contacts 40, 41, whereby the circuit will be reclosed.

This relay may preferabl `be combined with an indicating device o any kind, for instance, an electrlc lamp or the like which will indicate interruption of the current and, consequently, announce the fact that the refrigerator does not work normally, for some reason or other.

Byv means of a safety device of this kind, the great advantage is gamed that the circuit of the electric heatingv element 12 will be automaticall broken on an incidental interruption of the supply of water, whereby all risk of the refri erator bursting orotherwise being in'ure under sch circumstances is avoide While wel have shown and described spe cic devices for carrying out our invention, it l. is to be fully understood that other devicesi performi the desired functions may be employed an structural desi varied without departing from the spirit or 8009 0f $119 lll .I supplied with both tex'n erature resultant 10 auf? A1. A refrigerating systemj comprising a generator, an evaporator, heat rejecting means including an element continuously a hot fluid and a cold fluid in normal operation, a" source of heat for said generator arranged to continuously supply heat thereto, a thermostat responsive. to a of the supply of hot cold fluids to saidI element and means responsive to said thermostat to control the supply 'of heat to saidgenerator, said thermoing operative to interrupt the supply of supply of cold fluid to said element and being mactive during normal operation.

Q ,A refrigerating system comprising a generator, denser, means torontinuously supply cooling fluid to said absorber and to said con denser, said generator constituting a continu ous source of supply of heat to said condens'- er, a source of heat for said generatorl arranged to continuously supply heat thereto, a thermostat situated to be influenced by changes of temperature occurring in said condenser' and means responsive to said theran evaporator, an absorber, a con-r mostat to` control the supply of heat to.said generator, said thermostat being operative to mterrupt the supply of heat to the generator upon an .increase of tem rature to ahigh value due tocessation o sup ly of cooling fluid to said condenser and gelng inactive during normal operation. o 3.' vA heat operated refrigerating system normally loperating under a constant pressure,allv parts thereof being connected in open communication and being arranged for the circulation' of an absorption liquid, a cooling agent, and an^inert gas inthe presence of which the cooling agent evaporat-es, said parts including a generator, an evaporator and an element continuously and simultaneously suppliedwith both a hot fluid and a cold fluid in normal operation, a source of heat for said generator arranged to continuously supply hea't thereto and vmeans responsive to .a temperature resultant of the supply of hot and operative to control said source of heat.

4Initestimony whereof we aflix our signatures. n l

i BALTzARoARL vos PLATEN.

,CARL GEORGMUNTERS.

cold fluids to said element 50 

